title: Type I fractures of the odontoid process: implications for atlanto-occipital instability. Case report.
abstract: Only four cases of Type I odontoid fracture have been previously described in the English literature. Most authors consider this lesion to be stable, although the mechanism(s) of injury has not been clearly elucidated. A case of Type I odontoid fracture in association with atlanto-occipital and atlantoaxial dislocation resulting in death is presented. The normal ligamentous anatomy is reviewed and proposed mechanisms for this injury are discussed. The radiographic features of all reported cases of this type are reviewed. It is proposed that the Type I odontoid fracture is a likely manifestation of atlanto-occipital instability and rarely occurs as an isolated or stable injury.
authors.affiliation: Department of Neurosurgery, University of Florida, Gainesville.
authors.forename: E W
authors.initials: EW
authors.lastname: Scott
authors.forename: R W
authors.initials: RW
authors.lastname: Haid
authors.forename: D
authors.initials: D
authors.lastname: Peace
mesh_terms: D000328:Adult; D001268:Atlanto-Axial Joint / Q000293:injuries; D001269:Atlanto-Occipital Joint; D001368:Axis, Cervical Vertebra / Q000293:injuries*; D005260:Female; D050723:Fractures, Bone / Q000150:complications / Q000000981:diagnostic imaging; D006801:Humans; D004204:Joint Dislocations / Q000150:complications; D007593:Joint Instability; D008488:Medical Illustration; D009809:Odontoid Process / Q000293:injuries*; D011859:Radiography